Oxidation

Lees are the dead yeast cells, grape seeds and skins left over in the fermentation tank after fermentation. There are two types of lees; gross lees and fine lees.

Aging is a post fermentation process where wine rests in barrels (mainly oak) or bottles to undergo chemical changes that improves stability, develops complex flavors and clarifies the liquid.

The yield signifies the amount of grapes or wine produced from a specific vineyard area, commonly measured in tons per acre in the US, or hectoliters per hectare in Europe. Lower yields are associated with better quality, while higher yields produce lighter and less concentrated wines.

The harvest marks the end of the vine growing cycle, typically occuring between August and October in the Northern hemisphere. It is the stage where ripe grapes are picked from the vineyard to begin winemaking.

Maceration in wine is the process of soaking crushed grape skins, seeds and stems in the juice (must) to extract color, tannins and aroma compounds.

Malic acid is a naturally occuring organic acid in wine grapes, primarily found in unripe or cool climate berries. It gives a sharp acidity, tartness and freshness to wine.

Irrigation is the artificial application of water to vineyards to provide the necessary 25-35 inches of annual water in dry climates.

Racking refers to the process of transferring wine from one tank or barrel to another using gravity rather than a pump to separate clear liquid from sediment.